1. Field of the Invention
The present invention relates to a semiconductor device in which connection between constituent parts is realized by an insulating resin for bonding and sealing, and to a production method thereof.
2. Description of the Related Art
There is known a method for mounting a semiconductor device, where electrical and mechanical connections between a semiconductor element and a substrate are realized by a holding power of a thermosetting insulating resin. As an example of such a method, steps of mounting a semiconductor element in Laid-Open Patent Application No. 10-223686 are illustrated in cross-section in FIGS. 1A and 1B. First, a substrate 17 and a semiconductor element 11 are loaded onto a mounting machine. Then, as shown in FIG. 1A, an insulating resin 13 for bonding and sealing (hereinafter, referred to as “sealing resin”) is applied to the substrate 17 made of ceramic, glass, glass-epoxy, etc. on the side thereof where a wiring pattern 16 is provided.
The wiring pattern 16, which is made of Cr—Au, Al, Cu, ITO, etc., is formed by forming on the substrate 17 a metal layer by sputtering or vapor deposition, forming on the metal layer a resist having the wiring pattern 16 by a photo resist method, and etching the metal layer but the resist. The wiring pattern 16 may also be formed by printing or plating. The sealing resin 13 is a thermosetting resin such as epoxy resin, silicone resin, acrylic resin, etc.
Formed on an aluminum electrode of the semiconductor element 11 by electroplating, etc. is a protruding electrode 12 made of Au, Ag or Cu. The semiconductor element 11 is adsorptively held by a jig fixture 18 for pressing, heating and aligning purposes (hereinafter, referred to as “sealing jig fixture”) on the side thereof opposite to where the protruding electrode 12 is formed.
Next, as shown FIG. 1B, while aligning the protruding electrode 12 of the semiconductor element 11 with the wiring pattern 16 by the sealing jig fixture 18, the semiconductor element 11 is pressed onto the substrate 17. When the protruding electrode 12 formed on the aluminum electrode of the semiconductor element 11 is pressed against the substrate 17, the thermosetting sealing resin 13 between the protruding electrode 12 and the wiring pattern 16 is forced out of the space therebetween, and the protruding electrode 12 and the wiring pattern 16 are electrically connected.
Then, while maintaining the pressure, the sealing resin 13 is cured by providing heat thereto from the sealing jig fixture 18. Later, the pressure is released, and the bonding of the semiconductor element 11 to the substrate 17 is completed. When this process is finished, the protruding electrode 12 of the semiconductor element 11 and the wiring pattern 16 of the substrate 17 are held together by the contractile force of the thermosetting sealing resin 13, thereby maintaining their electrical connection.
As described above, it has now been discovered that in a conventional method of mounting the semiconductor element, where the liquid sealing resin is cured by providing heat while maintaining the pressure between the semiconductor element and the substrate by a sealing jig fixture, the pressure provided by the sealing fixture cannot be released until the curing of the thermosetting sealing resin is completed. Furthermore, although it is preferable that a sealing resin having a high glass transition temperature be used for better connection reliability, it generally takes more than 10 sec for such a thermosetting sealing resin to be cured, meaning that an expensive mounting machine is inevitably occupied for a long period of time and, therefore, the production cost cannot be reduced.